In recent years, technologies for processing fine patterns have been becoming more important in the manufacturing of semiconductor integrated circuits and optical elements, and one of such technologies is an imprinting method.
The imprinting method is a technology in which a mold having a concavo-convex pattern (hereinafter also referred to as a “mold”) is pressed against a material to be transferred formed on a substrate, whereby a pattern corresponding to the concavo-convex pattern is transferred onto the substrate, and a fine pattern at a nano-order can be formed by this imprinting method.
Focusing attention on the transfer process, the imprinting method is classified into two methods: a photo imprinting method and a thermal imprinting method. In the photo printing method and thermal printing method, a photocurable composition and a thermosetting composition are, respectively, used as a material to be transferred. The former photo imprinting method gains attention since it does not require heating and can form a pattern at room temperature, and thus has advantages that the pattern is minimally deformed and that positioning a substrate and a mold can be easily performed by using a transparent mold (for example, Patent Literature 1).
Examples of the mold that is generally used in this imprinting method include molds that are formed of quartz or metals such as nickel. As for the molds formed of quartz, patterns are formed on quartz substrates, and the like, by semiconductor fine processing technologies such as photolithography and etching. Furthermore, as for the molds formed of metals, patterns are formed by providing metal plating to a surface of a mold formed of quartz by an electric casting (electroforming) method (for example, a nickel plating method), and peeling this metal plating layer.
However, the molds prepared by such methods had problems in that they are very expensive and it takes long periods of time for the preparation.
Under such situations, a product formed by transferring a pattern on a resin by using the above-mentioned mold as a master mold, which is used as a resin mold, is disclosed.
The following Non-patent Literature 1 discloses a resin mold prepared by using a photocurable composition formed of a urethane methacrylate represented by the following formula and a photopolymerization initiator. However, Non-patent Literature 1 does not describe the durability relating to the resin mold disclosed therein.